It has been long recognized that the internal vaginal cavity in its normal collapsed state is of much wider dimension in its transverse plane than in its vertical plane. It is equally well known that the minimum dimension of the vagina is at the introitus while the maximum dimension is near the cervix. It is desirable therefore, when considering a tampon for catamenial use, to provide a structure which is in its initial state is of a size small enough to pass through the vaginal orifice without discomfort, and when once inside the vaginal cavity and beyond the restrictions of the orifice may be expanded, particularly in the lateral direction, to contact substantially all of surface of the vaginal walls from one side to the other in the vaginal cavity to prevent early bypass of the menstrual discharges from the cervix. Since the vaginal wall in its normal collapsed state is flaccid and has multiple folds and wrinkles which provide channels through which a significant portion of the menstrual fluids normally flow, it is also important that the absorbent tampon be as soft and conformable as possible, in order to conform to shape of the vaginal cavity and fit within these channels to minimize leakage.
The absorbent catamenial tampons now in general use comprise small, highly compressed, cylindrical plugs about three-eighths to one-half inch (about 1.0 cm to 1.3 cm) in diameter and from 11/2 to 21/2 inches in length (about 3.8 cm to 6.4 cm). Because of the need for absorbent capacity, they are usually formed from batts much larger in size than the vaginal orifice, and compressed to the small size indicated above in order to facilitate insertion. As fluid is absorbed, these compressed tampons are expected to expand (or re-expand) toward their original precompressed size, and to eventually become large enough to effectively block the vaginal cavity against fluid leakage or bypass. While it has been found that these compressed tampons perform their intended function tolerably well, even the best of them do not expand sufficiently, or fast enough, to provide a good transverse block against leakage even though the vertical block may be satisfactory. Further, most of these tampons generally use only a portion of their absorptive capacity before leakage. Since these tampons rely on some fluid absorption to expand, it is clear that fluid bypass and leakage can occur prematurely.
Numerous attempts have been made to solve this problem. Some approaches in the patent art suggest a tampon with a built-in mechanical expansion means, a typical example being U.S. Pat. No. 3,706,311 to Kokx et al. However, while a good transverse block appears to be produced, the mechanical expansion means disclosed in that patent is in the form of a flat spring-like element which after insertion permanently maintains the spread configuration of the tampon, may make it difficult to remove.
Another approach is described in U.S. Pat. No. 3,512,528 to Whitehead et al, which teaches the use of a sack of absorbent material collapsed to a small size for insertion and which after insertion is expanded by the introduction of a gas or a fluid internally of the sack. The multiple steps and complicated manipulation of the gas or fluid introduction means required when using this type of tampon detract from what otherwise appears to be an effective solution of the problem.
Still another approach is described in U.S. Pat. No. 3,857,395 issued to Johnson, et al. The Johnson, et al. patent teaches the use of an elongated inserter device over which a flat tampon is draped. The inserter is said to permit the draped portion of the tampon to be pulled, rather than pushed into the cavity from the point at which the tampon is supported on the leading end of the inserter. The inserter means is equipped with a bilateral expansion mechanism which at the user's option may be operated to transversely spread the tampon at the time of insertion. The inserter device described in the Johnson, et al. patent suffers from many drawbacks, however. The Johnson inserter device is a complicated device comprising a pair of hinged arms that are capable of laterally diverging at a hinge or joint. The angular nature of the hinged arms would appear to make that inserter uncomfortable to use. The complex nature of the hinged arms would also appear to make it difficult and expensive to manufacture. As a result, it would not be suitable as a disposable applicator.
Another problem that exists in deploying tampons having a greater transverse dimension within the vaginal cavity is that this greater transverse dimension of the vaginal cavity is roughly perpendicular to the vaginal opening.
One attempt to address this latter problem is described in U.S. Pat. No. 3,068,867 issued to Bletzinger, et al. The Bletzinger, et al. patent is directed to a tampon insertion device having a positioning indicator thereon. The device described in the Bletzinger, et al. patent comprises an insertion device for tampons which are either of cylindrical cross-section, or non-cylindrical cross-section but constructed to expand when subjected to fluids in a non-cylindrical shape. The insertion device is provided with an indicator that aids the user in inserting the tampon with its major cross-sectional axis transverse to the major axis of the vaginal opening.
The Bletzinger device, however, is awkward in that it requires insertion of the widest dimension of the tampon cross-wise to the narrowest dimension of the vaginal opening. Thus, a need exists for a tampon applicator which is capable of effectively deploying a tampon having a non-cylindrical shape in the vaginal cavity which does not require alignment of the widest dimension of the tampon cross-wise to the narrowest dimension of the vaginal opening.